Trailer brakes not working

[steve dunham]

Originally Posted by sallemann

That's good to know. How would you recommend cleaning the connectors?

You can use a FINE Emery board , just don't get overly aggressive.
You are only trying to polish the contacts not file off a bunch of metal.
Many motor starters use silver to plate the contacts and if you file them too much they are ruined . They cost around $100 to replace.

[arniesea]

Originally Posted by steve dunham

You can use a FINE Emory board , just don't get overly aggressive.
You are only trying to polish the contacts not file off a bunch of metal.
Many motor starters use silver to plate the contacts and if you file them too much they are ruined . They cost around $100 to replace.

I concur. I should have been more specific. Thanks Steve!

[steve dunham]

Originally Posted by arniesea

I concur. I should have been more specific. Thanks Steve!

I taught an electrical maintenance class at the local VoTech.
One thing I quickly learned is , instructions need to be fairly precise.
Your advise was right on , I was only trying to add aome context .

[AKCamper]

Originally Posted by sallemann

That's good to know. How would you recommend cleaning the connectors?

You used to be able to buy a small brush that was used for cleaning the sockets of distributor caps. It was a small 1/4 inch cylindrical brush. That is what I would use. looks like this.

[Jubal]

https://www.amazon.com/Innovative-Pr...nector+cleaner

[Bobnjudy]

Mine quit once last year. Called the installer and found out there was a recall on it. Got a free replacement and all was back to normal. These are cheaply made but essential devices.

[Bobbie54]

Reopening this thread because it sounds like my problem, not sure, though. I had everything working great coming home from Osoyoos. Now the brake controller says c for connected, shows numbers when I brake (manual or with the brakes) but the trailer brakes do not come on. I tried cleaning the contacts but probably didn't do too good a job. Connection seemed loose so I taped it so it would stay. All the lights work. Would the brake controller say the trailer is connected if I don't have brakes?

Last few replies have me wondering about the controller. I'll check for power to the brakes tomorrow but seems to me if the controller says the trailer is connected the connection is good.

Oh, and the one variable that I don't see how could have affected it but maybe I'm wrong- new tires on the Forester between then and now.

[tractors1]

Originally Posted by Bobbie54

Reopening this thread because it sounds like my problem, not sure, though. I had everything working great coming home from Osoyoos. Now the brake controller says c for connected, shows numbers when I brake (manual or with the brakes) but the trailer brakes do not come on. I tried cleaning the contacts but probably didn't do too good a job. Connection seemed loose so I taped it so it would stay. All the lights work. Would the brake controller say the trailer is connected if I don't have brakes?

Last few replies have me wondering about the controller. I'll check for power to the brakes tomorrow but seems to me if the controller says the trailer is connected the connection is good.

Oh, and the one variable that I don't see how could have affected it but maybe I'm wrong- new tires on the Forester between then and now.

Another method to check the trailer side is to have someone spin the tires and pull on the emergency disconnect switch so the trailer battery supplies the stop voltage. If the brakes brake then it's the controller side.

[Brian B-P]

Originally Posted by Bobbie54

Would the brake controller say the trailer is connected if I don't have brakes?

The controller determines if there is a connection by applying very short bursts of power, and monitoring to see if any current flows (it is supposed to flow only through the brake magnets). If there is a fault in the controller, or a short circuit in the trailer's brake wiring or the plug, it could look connected without the brake working.

• If there is a short circuit (or leakage) in the trailer wiring, and a good connection at the plug, it would look to the controller as if there is a good connection even if there is no current is going through the brake magnets.
• If there is a short circuit (or leakage) in the plug, it would look to the controller as if there is a good connection even if there is no current is going through the trailer wiring.
• If the controller is defective, anything could happen.

Even if all the wiring is good, power going through the brake magnets doesn't mean that the brakes will work properly - the linings could be contaminated with grease, or the brake mechanism could be rusty or broken, or the adjustment could be so far off that the brakes can't engage properly.

Originally Posted by Bobbie54

Oh, and the one variable that I don't see how could have affected it but maybe I'm wrong- new tires on the Forester between then and now.

I can't think of any way in which the tow vehicle's tires would have any effect on the operation of the controller or the trailer's brakes.

[gbaglo]

Originally Posted by tractors1

Another method to check the trailer side is to have someone spin the tires and pull on the emergency disconnect switch so the trailer battery supplies the stop voltage. If the brakes brake then it's the controller side.

But, not with the trailer connected to the tow, right? I believe that can damage the controller. Since power to the trailer brakes comes from the trailer house battery, tow doesn't need to be connected, I believe.

[War Eagle]

Originally Posted by Bobbie54

... Oh, and the one variable that I don't see how could have affected it but maybe I'm wrong- new tires on the Forester between then and now.

This is a stretch, but there is usually a dedicated brake wire that runs from the brake pedal/fire wall/engine compartment area, back underneath the chassis, to the 7-pin receptacle at the rear of the tow vehicle. If the tire shop put your tow vehicle up on a rack to mount the new tires, it seems there could have been a remote chance, very remote, that your brake wire got pinched or pulled lose somehow while on the rack. So, just to eliminate that as a possibility, it might be a good idea to follow that wire from front to rear to make sure it's still intact. It probably is, or you wouldn't be getting the "C" connected code. But it never hurts to check it out.
As a side story - we took our Toyota Highlander tow vehicle in for some engine work not long back, and somehow, the mechanic broke one of the leads off of an in-line auto-reset circuit breaker mounted on the firewall for our trailer brake wire. Got the car home, no trailer brakes (but also no "C" connect signal). Found and fixed the broken wire terminal on the in-line circuit breaker, and all was well again. Ya just never know what other people might do when they tinker under your hood.

[War Eagle]

While we're discussing this, what exactly does it take for a brake controller to display the "C" (connected) code? It would seem there needs to be a complete circuit somewhere with power from the TV/TT passing through something (or not) then finding a ground somewhere to complete the circuit. Could a break in a wire, that then rubs up against the frame, produce an out-of-normal-sequence ground, that then allows the "C" to light up on the controller, when in reality, power is not getting to where it is supposed to go to activate the brakes? (Sorry for all the commas, but that's just how my brain is working this morning.)

[Bobbie54]

Good question. And is it even the brake connection that tells the controller the trailer is attached?

I haven't done any testing yet- don't have a meter and haven't had time- but my thoughts are:

-it isn't the brakes themselves failing. They worked fine in May and neither side is doing anything now. The assumption has to be they are not getting an electrical signal

-whatever it is, it happens before the wire splits to both brakes (since neither is working)

-the controller "thinks" the brakes are there and is acting completely normally. No error messages. I don't know what this means, though, but when I looked at the Tekonsha site to troubleshoot the P2 the only similar problems said it shouldn't show a C. If the brake controller does not get feedback from the brakes themselves, this could be normal for a failure after the plug- or maybe at it.

-Is there anything that could go wrong with the trip wire that would do this?

[dfandrews]

I didn't see a mention of the controller mfr/model in the thread; but check your manual. Our Tekonsha P3 instructions, on page 9 and 10, indicate a series of diagnostics that the controller can go through to check a variety of the possibilities listed in this thread, including short detection, and current and voltage to brakes.

[Brian B-P]

Originally Posted by Bobbie54

-Is there anything that could go wrong with the trip wire that would do this?

What do you mean by "trip wire"?

Do you mean the cable which pulls the plug out of the breakaway switch? Then no - if the switch is not pulled, it does nothing; if it is pulled, the brakes go on with full power. The switch could be defective, but I don't see any way that the cable which pulls the plug out could be the source of a brake malfunction.

[Bobbie54]

Originally Posted by dfandrews

I didn't see a mention of the controller mfr/model in the thread; but check your manual. Our Tekonsha P3 instructions, on page 9 and 10, indicate a series of diagnostics that the controller can go through to check a variety of the possibilities listed in this thread, including short detection, and current and voltage to brakes.

It's a Primus. Troubleshooting only includes if the c is not there or the brakes don't work with the pedal but do with the manual. Not what's happening. I'm going to try calling them. The instructions don't include the series of diagnostics; e-trailer does but as the first involves cutting a wire I'd rather not start there.

[Bobbie54]

Originally Posted by Brian B-P

What do you mean by "trip wire"?

Do you mean the cable which pulls the plug out of the breakaway switch? Then no - if the switch is not pulled, it does nothing; if it is pulled, the brakes go on with full power. The switch could be defective, but I don't see any way that the cable which pulls the plug out could be the source of a brake malfunction.

That's what I meant. I didn't think so but just checking.

[Iowa Dave]

I would recommend an electrical contact cleaner that you you can buy at an auto parts store or hardware store. I like a product made by CRC red and white can. About $ 5 or 6 and not oily like wd40. Spray it on, use a q tip to swab the tips and plug in holes out. You'll get some funky stuff off them which will improve continuity. I use it every spring to clean up any ambient salt spray deposits which can be corrosive. Emery boards, fine files etc are ok you just don't want to bear down and take off metal. Just my $.02
Iowa Dave
Dave

[bigalaska2012]

Our trailer was brand new and 250 miles away the break away switch shorted out

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[Rossue]

Did you get the Primus from ETI? For very little more a P3 is a much better choice.